How do you name organic compounds with double bonds?

Organic compounds with double bonds are named using the IUPAC system, with the suffix '-ene' indicating the presence of a double bond.

In the International Union of Pure and Applied Chemistry (IUPAC) system, the presence of a double bond in an organic compound is indicated by the suffix '-ene'. This is added to the end of the root name of the compound, which is based on the number of carbon atoms in the longest continuous chain. For example, a compound with two carbon atoms and a double bond is called 'ethene'.

The position of the double bond is also important in the naming process. The carbon atoms in the chain are numbered from the end nearest to the double bond. The number of the carbon atom where the double bond starts is then included before the '-ene' suffix. For instance, if the double bond starts at the second carbon atom in a six-carbon chain, the compound is named '2-hexene'.

If there are multiple double bonds, the compound is named with a prefix such as 'di-', 'tri-', 'tetra-', etc., followed by '-ene'. The positions of all the double bonds are indicated by numbers before the '-ene' suffix. For example, a compound with two double bonds at the first and third carbon atoms is named '1,3-butadiene'.

In addition, if there are other functional groups or side chains present, these are also indicated in the name. The rules for naming these are complex and depend on the specific groups or chains present. However, in general, they are named as prefixes to the main chain, with their positions indicated by numbers. For example, a compound with a methyl group at the second carbon atom and a double bond at the third carbon atom is named '2-methyl-3-butene'.

Remember, practice is key to mastering the naming of organic compounds. The more you practice, the more familiar you will become with the rules and the easier it will be to name compounds correctly.